DESCRIPTION: (Adapted from applicant's description) This revised application describes experiments in which developing mice will be subjected to unilateral cerebral hypoxia-ischemia produced by ligation of one common carotid artery followed thereafter by exposure to systemic hypoxia by the inhalation of reduced concentrations of oxygen. During the course of and following the cerebral hypoxia-ischemia, specific experiments will be performed to ascertain the nature and extent of the ultimate tissue injury. Specific therapeutic interventions also are proposed. Other developing mice will be subjected to excitotoxic injury by the injection of glutamate agonists into selected areas of brain. As with the hypoxia-ischemia studies, experiments are proposed to ascertain the extent of the ultimate morphologic abnormalities as well as the effect of therapeutic interventions.